SYNONYM, ANTONYM, HYPONYM

A synonym is a word or phrase that means exactly or nearly the same as another word or phrase in the same language. Words that are synonyms are said to be synonymous, and the state of being a synonym is called synonymy.

Synonyms can be any part of speech (such as nouns, verbs, adjectives, adverbs or prepositions), as long as both words belong to the same part of speech. Examples: 

Antonym is a word that has the opposite meaning of another word. It refers to a word that is completely different from another one. They also are called opposites. The opposite of a antonym is a synonym. Hot and cold are antonyms, whereas hot and torrid are synonyms. For instance, the antonym of 'hot' may be 'cold.'

Hyponymy is a relation of inclusion. In the words of Lyons (1968, 453), "...the meaning of tulip [or rose or geranium] is said to be 'included' in the meaning of flower." To take another example from Lyons (1968, 453), "the 'meaning' of scarlet is said to be 'included' in the 'meaning' of red." When represented hierarchically, "The 'upper' term is the superordinate and the 'lower' term the hyponym" (Palmer: 1981, 85). Therefore, the term tulip is a hyponym with respect to flower, while tulip, rose and geranium are co-hyponyms, i.e. hyponyms of the same superordinate term. Looking at this from the opposite angle, flower is the superordinate with respect to tulip, rose and geranium. (It should be noted that the designation of a term as a superordinate or hyponym is relative, not absolute. For example, tulip is hyponym of flower, but in turn would be a superordinate of parrot tulip).